I'm a bit confused about using の particle with quantity words (e.g. たくさん, 多く, ほとんど, etc.) when modifying nouns (たくさんの本 / たくさん本 ; 多くの人 / 多く人). Is の necessary in such cases? If yes, why I sometimes find Japanese people saying both たくさん[something] and たくさんの[something], or いっぱい[something] and いっぱいの[something]?

Hi, I'm no expert so don't quote me on this, but i'm pretty sure that both are correct.In casual speech it's not uncommon for Japanese speakers to make all sorts of different contractions by dropping words and parts of words, in many cases to make different sentences and constructions easier to say.たくさんの人 and たくさん人 really are the same thing, と思います＾＾

For written Japanese however, i'd personally always write たくさんの人 though;

I have always knew that adjectives like "takusan no" or "ippai no" keep off their particle (の) only when linked with the polite copula です.Anyway, I've never heard before something like たくさん人/本 and so on...「たくさん人/本」って聞いたことありませんね。

Minaraiさん, I think we are both singing from the same hymn book here It does appear to me that たくさん人 isn't 100% grammatically correct (but i could very definately be wrong), and that's reflected in its usage on google for example. たくさん人 clocks up 143,000 hits, and たくさんの人 2.9Million hits. Maybe thats just 143,000 lazy writers?

It should be noted that the number of hits that google gives you is a very rough estimate, and it can sometimes be completely wrong. (For instance, there are rare occasions where a term will only show up on a tiny handful of pages, but Google will tell you there are 100,000 or more hits.)

What inuinu-san said is that if you see something like たくさん本を読んだ, the structure is like #1 (たくさん is connecting to 読んだ) but the order has been shifted.

Re: the google hits, I think the number only gets seriously skewed if you type something in and it says "Did you mean X?" In that case the hits for the original phrase get mixed in with the hits for the suggestion. So if you type a made-up word or gibberish you may get hundreds of thousands or even millions of hits.

Yudan Taiteki wrote:Re: the google hits, I think the number only gets seriously skewed if you type something in and it says "Did you mean X?" In that case the hits for the original phrase get mixed in with the hits for the suggestion. So if you type a made-up word or gibberish you may get hundreds of thousands or even millions of hits.

Nope. Google for "gakkou no ato" (in romaji and in quotes) and it will say 150,000 hits, with no "Did you mean X?". Scroll down and you'll see it also says only two pages of hits.